So the situation is:
You have two table, table1 and table 2, both has a column named to 'Initiative',
and within the Galley, the Title1 Label has been configured to 'Initiative' under Table1, and for the SubTitle, you would like to sum up the 'Realized Savings' from Table 2, for all the 'Initiative' column value equals to the one configured under the Title1 from Table1,
If this is what you would like to achieve, then please take a try to switch the formula as blow:
Sum(Filter('[dbo].[Table2]';Initiative=Title1.Text);Realized_Savings)
The column name for "Realized Savings" might be different from the above, please consider select the proper one from the Dropdown when writing the formula.
Let me know if that would work as expected.
Regards,
Michael