If I'm understanding you correctly, you are looking for who on your wikitree family tree that has DNA. Many of these wont. It's easiest to run a gedmatch one to many report and look for a wikitree link, however if you really want to go through wikitree there's a couple ways I know of to look.
1. The DNA confirmation page will show potential DNA matches as hints under each ancestor. For instance under one of my great grandfathers, 5 DNA test appear for relatives of his that have been tested. One is mine and I unfortunately don't match the other 4 kits.
2. You can look to the right side of the screen on each person's page and it will say "DNA Connections. It may be possible to confirm family relationships with ______ by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA. However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line. It is likely that these autosomal DNA test-takers will share DNA with ____:" or there may be no one who is known to be related who has taken a DNA test and put that on wikitree. I've found wikitree is most helpful at recording DNA results and maintaining my tree, more than finding the DNA connection.
3. If you are searching for people in general who have had the name Coetzee, which will exclude many of your relatives and include many that possibly aren't related (except in the general and very distant all humans are related sense) you can check out https://www.wikitree.com/index.php?title=Special:DNATests&s=Coetzee (If you want another surname you can just change the surname in the link after the = )
For all of these it gives you a possible kit to compare against your own, but it redirects you to gedmatch to compare. WIkitree doesnt run any system to compare kits itsself.
Did that help?