Can we draw mutlipath different width and spacing at the same time?

I think this should do what you want (it would have helped if your picture showed what you want, rather than what you're getting, so I had to guess that this was indeed what you want). I've attached two pictures (merged together) showing the original multipart path at the bottom, and then after reshape and stretch. It has Metal1 on the bottom, Metal3 on the top, a strap of via1 and via2 on the gnd at the upper and lower edge, and then 4 tracks in the middle.

cvId=geGetEditCellView()
points=list(0:0 40:0)
mainWidth=1
mainSpacing=1
gndWidth=2.0
gndSpacing=1.5
nTracks=4
mainLayer="Metal2"
bottomLayer="Metal1"
topLayer="Metal3"
viaLayer1="Via1"
viaLayer2="Via2"
viaWidth=0.5
viaSpacing=0.5

offsetPaths=nil
for(i 1 nTracks-1
    offsetPaths=
        cons(
            list(
                ?layer mainLayer
                ?width mainWidth
                ?sep -i*(mainWidth+mainSpacing)
            )
            offsetPaths
        )
)
offsetPaths=constar(
    list(
        ?layer mainLayer
        ?width gndWidth
        ?sep mainWidth/2.0+gndSpacing+gndWidth/2.0
    )
    list(
        ?layer mainLayer
        ?width gndWidth
        ?sep -(nTracks-1)*(mainWidth+mainSpacing)-mainWidth/2.0-gndSpacing-gndWidth/2.0
    )
    offsetPaths
)

subRects=foreach(mapcan viaLayer list(viaLayer1 viaLayer2)
    list(
        list(
            ?layer viaLayer1
            ?width viaWidth
            ?gap 'distribute
            ?space viaSpacing
            ?sep mainWidth/2.0+gndSpacing+gndWidth/2.0
            ?beginOffset -viaSpacing
            ?endOffset -viaSpacing
        )
        list(
            ?layer viaLayer1
            ?width viaWidth
            ?gap 'distribute
            ?space viaSpacing
            ?sep -(nTracks-1)*(mainWidth+mainSpacing)-mainWidth/2.0-gndSpacing-gndWidth/2.0
            ?beginOffset -viaSpacing
            ?endOffset -viaSpacing
        )
    )
)

topBotWidth=nTracks*(mainWidth+mainSpacing)-mainSpacing+(gndSpacing+gndWidth)*2
topBotCent=gndWidth+gndSpacing+mainWidth/2.0-topBotWidth/2.0

foreach(topBotLayer list(bottomLayer topLayer)
    offsetPaths=cons(
        list(
            ?layer topBotLayer
            ?width topBotWidth
            ?sep topBotCent
        )
        offsetPaths
    )
)

rodCreatePath(
    ?cvId  cvId
    ?layer mainLayer
    ?width mainWidth
    ?pts points
    ?offsetSubPath offsetPaths
    ?subRect subRects
)

I think this should do what you want (it would have helped if your picture showed what you want, rather than what you're getting, so I had to guess that this was indeed what you want). I've attached two pictures (merged together) showing the original multipart path at the bottom, and then after reshape and stretch. It has Metal1 on the bottom, Metal3 on the top, a strap of via1 and via2 on the gnd at the upper and lower edge, and then 4 tracks in the middle.

cvId=geGetEditCellView()
points=list(0:0 40:0)
mainWidth=1
mainSpacing=1
gndWidth=2.0
gndSpacing=1.5
nTracks=4
mainLayer="Metal2"
bottomLayer="Metal1"
topLayer="Metal3"
viaLayer1="Via1"
viaLayer2="Via2"
viaWidth=0.5
viaSpacing=0.5

offsetPaths=nil
for(i 1 nTracks-1
    offsetPaths=
        cons(
            list(
                ?layer mainLayer
                ?width mainWidth
                ?sep -i*(mainWidth+mainSpacing)
            )
            offsetPaths
        )
)
offsetPaths=constar(
    list(
        ?layer mainLayer
        ?width gndWidth
        ?sep mainWidth/2.0+gndSpacing+gndWidth/2.0
    )
    list(
        ?layer mainLayer
        ?width gndWidth
        ?sep -(nTracks-1)*(mainWidth+mainSpacing)-mainWidth/2.0-gndSpacing-gndWidth/2.0
    )
    offsetPaths
)

subRects=foreach(mapcan viaLayer list(viaLayer1 viaLayer2)
    list(
        list(
            ?layer viaLayer1
            ?width viaWidth
            ?gap 'distribute
            ?space viaSpacing
            ?sep mainWidth/2.0+gndSpacing+gndWidth/2.0
            ?beginOffset -viaSpacing
            ?endOffset -viaSpacing
        )
        list(
            ?layer viaLayer1
            ?width viaWidth
            ?gap 'distribute
            ?space viaSpacing
            ?sep -(nTracks-1)*(mainWidth+mainSpacing)-mainWidth/2.0-gndSpacing-gndWidth/2.0
            ?beginOffset -viaSpacing
            ?endOffset -viaSpacing
        )
    )
)

topBotWidth=nTracks*(mainWidth+mainSpacing)-mainSpacing+(gndSpacing+gndWidth)*2
topBotCent=gndWidth+gndSpacing+mainWidth/2.0-topBotWidth/2.0

foreach(topBotLayer list(bottomLayer topLayer)
    offsetPaths=cons(
        list(
            ?layer topBotLayer
            ?width topBotWidth
            ?sep topBotCent
        )
        offsetPaths
    )
)

rodCreatePath(
    ?cvId  cvId
    ?layer mainLayer
    ?width mainWidth
    ?pts points
    ?offsetSubPath offsetPaths
    ?subRect subRects
)