Manipulation of Row Level Subtotal

I think the problem can be narrowed down to

if there is a way DAX can return which level is currently expanded in matirx, and based on that manipulate each measure. But I dont think DAX has a way to  return this info jeffrey_wang 

debugger6 = 
VAR L1 =ISINSCOPE ( dim_L1[L_1] )
VAR L2 =ISINSCOPE ( dim_L2[L_2] )
VAR L3 =ISINSCOPE ( dim_L3[L_3] )
VAR tbl =
    SWITCH (
        TRUE (),
        L1 = TRUE () && L2 =FALSE(),
            TOJSON (
                SUMMARIZECOLUMNS (
                    ROLLUPADDISSUBTOTAL ( 'dim_L1'[L_1], "IsGrandTotalRowTotal" )
                ),
                -1
            ),
        L1 = TRUE ()
            && L2 = TRUE () && L3=FALSE(),
            TOJSON (
                SUMMARIZECOLUMNS (
                    ROLLUPADDISSUBTOTAL (
                        'dim_L1'[L_1],
                        "IsGrandTotalRowTotal",
                        'dim_L2'[L_2],
                        "IsDM1Total"
                    )
                ),
                -1
            ),
        L1 = TRUE ()
            && L2 = TRUE ()
            && L3 = TRUE (),
            TOJSON (
                SUMMARIZECOLUMNS (
                    ROLLUPADDISSUBTOTAL (
                        'dim_L1'[L_1],
                        "IsGrandTotalRowTotal",
                        'dim_L2'[L_2],
                        "IsDM1Total",
                        'dim_L3'[L_3],
                        "IsDM3Total"
                    )
                ),
                -1
            )
    )
RETURN
    tbl