Hello @nephring,
When you use a Router, every route has its own set of processes and data when you go on.
However, there is one solution to use the previous route to process data into the next route.
Use the “Set Multiple Variable” at the end of the route. https://www.make.com/en/help/tools/tools#set-multiple-variables
Then the start of the next route use “Get Multiple Variables” https://www.make.com/en/help/tools/tools#get-multiple-variables
Now in your case, set the variable after Array Aggregator, Then call that variable back at the start of the another route using “Get Multiple Variables” and use it on BaseLinker.
Also, make sure to cross-check variable names.
I hope this helps.