In the Feature Manager you should see the [Σ] symbol with Equations next to it. RMB click on it and select Edit Equation to list all equations in the part. You will then have to examine each one to find the referenced fillet.
When creating equations it is helpful to use the Comments column to give a description of what the equation is for.
Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091