What you are trying to do?
VLOOKUP function returns a single value from range. In your case it is string "BHGGG";
Then you add to this string another and you get "BHGGGList"
And then you use INDIRECT to read some value from cell BHGGGList !???


Are you trying to create dynamic Data Validation List for cell B7? There are 3 possible ways to create a Data Validation List:
1. By values - you enter delimited value list into Source field (like "red","blue","green"). (I don't know what you use as list delimiter, for me it is semicolon.);
2. By reference to range of cells. Referred cells MUST BE ON SAME SHEET as cell with Data Validation List defined. The source will be like '= $X$2:$X$12';
3. By reference to Named Range (fixed or dynamic). The range of cells defined as Named Range can be on any sheet of workbook. The source will be like '=YourNamedRange'


As follows, you can create a dynamic Data Validation List only using dynamic Named Ranges.