Filter not working with select field

[Ginakate8]

Hi - looking for some assistance with an interface where I am looking to achieve filtering according to a selection. 

The example is as follows, I have a timeline view which we will filter by a 'Customer' field, which we would then subsequently want a field which we have called 'Deals' that only relating to the specific customer. The currently 'Deal' filter is a look up field which comes from a separate base. 

 

[TheTimeSavingCo]

I don't think this is possible at this time I'm afraid.  I tried using a linked field with dynamic conditions to do this as well and that didn't work either

To workaround this, I ended up updating my 'Deals' table primary field to be a combination of the customer name + the deal name so that i could at least easily filter by the customer name, does that make sense?