Custom measure

Here is one way.

1) Create dimension tables (Modeling -> New Table) for the fields Project and Roles using the follwoing pattern:

DProject =
DISTINCT (
    UNION (
        VALUES ( 'FTE Budget Table'[Project] ),
        VALUES ( 'Resource Table'[Project] )
    )
)

2) Set up single direction 1:* relationships between these dimension tables and their corresponding fields in the fact Tables. The model looks like this:

 3) Create the following measures to use in the visual:

Sum FTE Budget = 
SUM('FTE Budget Table'[FTE budget])

Sum Project Hours =
IF (
    ISBLANK ( [Sum FTE Budget] ),
    BLANK (),
    SUM ( 'Resource Table'[Hours] ) + 0
)

4)  create the visual using the fields from the Dimension tables and the measures to get:

I've attached the sample PBIX file