Question related to finding duplicates

Excel 

Let's say the first/middle/last names are in A2:A50 and the last/middle/first names in B2:B50.

Select A2:A50.

I will assume that A2 is the active cell in the selection.

On the Home tab of the ribbon, select Conditional Formatting > New Rule...

Select 'Use a formula to determine which cells to format'.

Enter the formula

=ISNUMBER(MATCH(TRIM(RIGHT(SUBSTITUTE(A2," ",REPT(" ",255)),255))&" "&TRIM(MID(SUBSTITUTE(A2," ",REPT(" ",255)),255,255))&" "&TRIM(LEFT(SUBSTITUTE(A2," ",REPT(" ",255)),255)),$B$2:$B$50,0))

Click Format...

Activate the Fill tab.

Select a highlight color.

Click OK, then click OK again.

Next, select B2:B50.

Do the same as above, but with the formula

=ISNUMBER(MATCH(TRIM(RIGHT(SUBSTITUTE(B2," ",REPT(" ",255)),255))&" "&TRIM(MID(SUBSTITUTE(B2," ",REPT(" ",255)),255,255))&" "&TRIM(LEFT(SUBSTITUTE(B2," ",REPT(" ",255)),255)),$A$2:$A$50,0))