Importing a dimension from one dimension list to another

Hey,

I have a dimension list with “Actual Vendors”, that are created from our actuals transaction list. 

I’ve created a “budget category” dimension in the “actual vendor” dimension list, where I will tag and create new budget categories for each “actual vendor”, also created a boolean column, which checks wether I tagged the “Actual Vendor” or not. 

I’ve also imported our Vendor Budget list, where I’ve tagged an “Actual Vendor” to each “Budget Vendor”. 

I know want to add/import the “Budget Category” to the Vendor Budget list, mapping it from the Actual Vendor dimension list on the aligned “Actual Vendor” dimension. 

I’ve tried this formula but get the error message: 

Error: Dimension error: the Dimensions of the formula and the current Metric structure are not compatible. Can't implicitly remove Vendor Dimension(s) on non numerical Metric.

if(vendor.'Is Budget Category?',vendor.'Budget Category','FY24 Budget Dimension Vendor List - Development'.'Budget Only Vendor')]