The operators in the domain are prefix. Prefix notation requires the operators to be placed first and then the operands. This means that A and B should be translated in the prefix expression as and A B. Following this form, and based on you expression, this is the way to convert it to prefix and than writhe the domain:
A and B or C or (D and E) => and A B or C or (D and E) => or and A B C or (D and E) => or or and A B C (D and E) => or or and A B C and D E
So, the expression you need to write is or or and A B C and D E. There is convention that and can be omitted, so the final expression is:
or or A B C D E which in code is ['|','|',('branch_id','=',parent.branch_id),('tgl_penyerahan_bpkb','=',False),('finco_id','=',parent.partner_id),('customer_id','=',parent.partner_id),('finco_id','=',False)]
I hope this helps. Prefix notation can be confusing for a first time, so here is a site that can help you understand the notation http://www.cs.man.ac.uk/~pjj/cs212/fix.html