Okay so I have solved Part of the Problem. Let me update a little bit. instead of using a Reusable RG for the Category Lists (Favorites, Nearby, Recommended) I have just put it on the page and the sub-navigation and RG now easily communicate.
My End Result is to achieve the following UX Screen Layout and here is where I currently sit.
Where I am Currently Struggling is getting the Businesses Listings of the “Current Cell’s Category” and passing that to the RG of Businesses in that category. For the Business Listings I am currently using a Reusable Repeating Group Because that is what I have learned, through trial and error, achieves my design goals.
So I need help passing the data between the two Elements (Categories going up & down with Business Listings in those categories going left & Right)