I wouldn't say useless, but definitely counter-intuitive.
"Look for" determines the results you get and "Look by" determines what the rules apply to. Let's say you want to find a feature that contains your dimension name "equal to" [dxxx]. Then you set look for to feature and look by to dimension. Now it will find all features that contain a dimension named [dxxx]. Powerful tool but I don't use this particular search option very often.
I find myself using the search tool when I'm in a very large assembly, trying to place a component to datums. Datums are hidden by default to keep the clutter down, so I search for a datum plane (or axis, etc.) and change the "Look in" to the component, skeleton, asm, etc. that I want; set the name to *, and flip through the few planes that show up in the results to quickly find the datum of choice. This way I don't have to mess around with turning layers on/off and trying to find a datum through the dense sea of choices and right click selecting forever in the giant master assembly.
Finding a feature by name can be useless unless you've specifically named it. This may also be a bug. It seems the default names that get applied to features aren't the real names. Open a part and do a search "is equal to" for features named * and you'll see only features that don't have a default name applied.
However if you do a search for "is not equal to" for features named * and all of the default named features show up. a feature default-named "Extrude 2" in the tree actually shows up as "EXTRUDE_2" in the search results but is not searchable by this alternate name. It's like not only do they not have a name, the field "name" doesn't even exist for the feature. Weird indeed.
Creo 2 M070
