A really easy, fast way that I can think of giving you that, is by creating a block and passing the id of the record/records that you are displaying. And inside of the webblock you are counting with a data action how many records there are. And then you put on an expression the return value from the data action.

By doing that you are doing what you want.

EDIT:

Bruno Freitas's solution is the best in this case.

Kind Regards,

Márcio

Hi @Fran C ,

An alternative, and considering that you only need the count is to modify your aggregate in screen 1. Lets say your records for screen 1 come from entity 1, and the records for screen 2 from entity 2. 

On the screen 1 aggregate you can left join entity 2, and group the entity 1 attributes, performing a count over the id attribute of entity 2.

Cheers,

Bruno

People let's not repeat the same solution multiple times, if it is provided by someone no need to suggest the same hours later. There are enough other questions that deserve that yet not have a good solution proposed you could focus on.