When timesheet is created with 2 lines having 2 different projects and hours entered on same day for both projects id let say example Project X has 4 hours on 22/august/22 and Project Y has 2 hours on 22/august/22 

The voucher entries in accounting source explorer, should show one line for Project X for $abc amount and a separate line for Project Y with $abc amount.

This should work without making project id as one of the financial dimensions.