How can I create filter based on two different fields with OR operator between them in Power View?

For example I want to filter my data based on next filter expression:

lead_veh_of_interest starts with 'BMW 1'
OR
sale_model starts with 'BMW 1'

how can I achieve this?

I found acceptable solution (thanks for all suggestions - it was very helpful).

First of all I redesigned my model and (how @Mike_Honey suggsts me) created dedicated table with consolidated information I want to filter. Next I connected this new table with existing tables and created hierarchy from fields I want to give to the end users for step-wise filtering (previously I split down old fields contained information I want to filter into more granular level). Now it is possible to filter data by any combination of models in any combination of request types (sale, lead, competitor, etc) using hierarchy.