Thank you this is very helpful, but it is only capturing the max value, which is 3.
A- Location; B- Name; C - number of visits; D - max number of visits
1. Adelaide; Sara Poon; 1;0
2. King; Jason Ex; 2;0
3. Wellington; John Smith; 1 ; 0
4. Bill; John Smith; 1; 0
5. King; Jason Ex; 3; 3
6. Adelaide; Joe Shoe; 2; 0
7. Adelaide; Joe Shoe; 1; 0
8. King; Jason Ex; 1;0

But what I am looking for is to capture is if columns A (location) and B (name) match, then capture the max number of visits D from column C
A- Location; B- Name; C - number of visits; D - max number of visits
1. Adelaide; Sara Poon; 1;1
2. King; Jason Ex; 2;0
3. Wellington; John Smith; 1 ; 1
4. Bill; John Smith; 1; 1
5. King; Jason Ex; 3; 3
6. Adelaide; Joe Shoe; 2; 2
7. Adelaide; Joe Shoe; 1; 0
8. King; Jason Ex; 1;0