User input to drive column result

Hello.

Looking for advice/help from the knowledge base.  I am trying to create a measure that affects a column, based on user (slicer) input.

The columns are as follows:

I have set up "single" select slicers for Producer, Location & Product as well as a slicer for a step change (from -20% to 20%) using 

Step_Change = GENERATESERIES(-.20, .20, 0.005)

My goal is to change the volume by the selected percentage of a specific selection of Producer/Location/Product.

But not affect all volumes just the ones that meet such criteria.

I have been using :

IF (selectedvalue(customer)= MAX(customer(from a column)) && selectedvalue(location)= MAX(location(from a column), MAX(volume(from a column))*(1+selectedvalue(%_Change)), MAX(volume(from a column))

But it either changes all the volumes or none (depending on the slicer connections/interactions).

The link to sample pbix, is Volume Change PBIX