to count values ​​between two fields

I am trying to create a measure in which I can present a value that presents the information if a customer made a purchase in a company other than one that he has already bought ... and not only if he bought but also how many purchases he made ........ all the information is in the same table .... already tried everything but nothing so far.....

I think an if case can solve the problem but I do not know how to do it.

This is the measure I'm trying to create:

Cotave = CALCULATE ( [Qtd. Active clients]; 'PBI_FAT_TT' [COMPANY NAME] IN {"Cotave", "Elmaz" )

[Qtd. Active clients]; shows the number of customers and "Cotave" and "Elmaz" are the companies Qty Active Customers for