Hi Leslie,
This unmerged column from the other query can not be directly included in the block.
Try below workaround:
Create a detail variable for those columns which are not merged from second query and associate that to the merged dimension.
For eg.
If query 1 has columns a,b,c,d and query 2 has a,e,f and all dimensions types, than you can use in a single block merged dimension a with either e,f or a with b,c,d.
The workaround to include e and f column from query 2 in block having a,b,c,d would be to create detail variable for the column e and column f and associate these two variables to the merge dimension a and use these detail variable instead of original columns in the block.
Let us know, if this is working.
Thanks
Gaurav