DoubleClick stack and GA question

We have a situation w a client where I was just told that the display & programmatic ad serving done under one account name. However, they house 6 individual brands.

For the paid search side of things, they are using DS and have separate accounts - one for each brand.

But this isn’t the case for programmatic & display. And now they want to link DCM to GA, and because it’s not brand-specific (and because I ONLY have brand-specific GA data properties set up), how would I do this?