AX Item Group Dimension data not displaying

Dears.

I have dimensions two are default of AX one is custom legal entity is working fine but unable to see any data in Item Group which is AX dimension not custom.I think it is linked with Inventory Classes but not working ?

1-legal Entity  (Company Name )- AX LEGAL ENTITY

2-Buiness Line (FMCG/RETAIL/WHOLE SALE) -CUSTOM

3-Item Group DEFAULT OF AX(milk,detergents, etc) i have created products and item classes in AX but not showing in drop down of Dimensions.

Thanks a lot for help and replying.