You connect rigid bodies with joints. You would make your rigid bodies in the correct positions, then make fixed joints to attach them. This shows 4 primitive objects attached to each other...
sync on: sync rate 0
phy start
make object box 1, 100,2,100
phy make rigid body static box 1
make object box 2, 10,10,10
position object 2, 0,50,0
phy make rigid body dynamic box 2
make object box 3, 5,5,5
position object 3, 0,60,10
phy make rigid body dynamic box 3
make object box 4, 10,10,10
position object 4, 20,50,0
phy make rigid body dynamic box 4
make object sphere 5, 6
position object 5, 20,40,2
phy make rigid body dynamic sphere 5
phy make fixed joint 1,2,3
phy make fixed joint 2,2,4
phy make fixed joint 3,2,5
position camera 0,30,-50
point camera 0,5,0
do
phy update
sync
loop