Filtering in a visual (excluding cases) based on values in another column

Hi,

I work in logistics and I am working on a visual for our inbounds department, so they can quickly see which locations are empty (so new products can be placed at this spot). 

I have two variables:

Location (Systemwide) - Contains all locations that we have within our system (at which products are currently or can be placed). 

Stock Location - Contains the locations our stock is located at, meaning that only locations that currently have stock, are displayed in this column.

For the visual I want (displaying only the empty locations), this would mean that I would have to calculate a new column based on these two locations. That is; I want values that are positioned in both columns (Location & Stock Location), to be assigned a 1, and values that are positioned in only one column (Location) to be assigned a 0. This would mean that I could filter one of these out and be left with only the empty locations.

I have no idea how to start on this, however. So any help would be greatly appreciated. If anything is unclear, please feel free to ask below. 

Thanks in advance!