IFeature::GetParents and IFeature::GetChildren are what you need. It isn't clear whether these are the API calls you speak of, since you didn't include the interface name. Please do so in the future to avoid ambiguity. (There are several interfaces that have members with "GetChildren" and "GetParents".) API calls are written out like this:
Anyway, if I remember correctly, IFeature::GetParents doesn't return the entire list of parents that you would expect. So it might be necessary to get feature X's parents by seeing what earlier features have feature X listed as a child.
Thanks Keith, I'll give that a try.
The reference I found was in a sample macro in the API help that used "SldWorks.Feature.GetParents"
That example does use the API calls I suggested. Note how they are written:
If you look at the declarations, swFeat is declared as SldWorks.Feature, which refers to IFeature.