Output of a rule expression

Hi! I´m creating a rule expression to return a value based on the logged in user, and use this value in an interface.

In this case, I want to return the value "Proveedor 2" and show it in the interface. But the problem is that, when I try to reference the rule as a local variable, the following is shown.

My local variable configuration is:

I think the problem is in the test output of my expression rule. When I put it in raw format, the same text which appears in the interface is show (I just want "Proveedor 2"):

1)Image of expression Rule

2) Expression rule output in various formats

In this case, I would like to extract just the "Proveedor 2" output. How can I do this?