In the Code locations area memory problems are referenced by file:line and function name. To see the variable name you can expand the problem line it will be shown in the code. So you can see the variable name from the code line. The variable name is not highlighted, only the code line containing it.
Indirect tip is type of the problem. In the example below problem X4 is in the col struct. Description says it is Read. In expression B=(int) (col.b*255); only col is read, so this is the problem variable.
If you want to see col directly highlighted inside the expression, Im afraid this is not supported. Analysis allows to find instruction address, where problem occurred. From the address it can find line in the sources, but not exact data object.