Hi
Solman is a dual stack system (One instance for both Java & Abap sharing the same SID).
I do not think it is possible to use the Solman Java stack for a BW system.
In the BW scenario the Java stack must use the BW abap stack for user accounts (UME source) but the solman Java stack is already configured to use its abap stack as an UME source... and to my knowledge there can only be one abap system as an UME source...
Best regards