Support descendant specifier in predicates

[LeeSmet]

Given the following xml document

<root>
  <a><b><c>...</c></b></a>
  <a><b>...</b></a>
  <a><b>...</b></a>
  <a><b>...</b></a>
</root>

It seems like there is currently no way to specify an Xpath expression so that only the nodes get selected because they have a grandchild somewhere. I'm looking for support for something like this
//a[.//c] or alternatively //a[b/c].
Currently, such Xpath expressions fail with etree: path has invalid filter [brackets].

[beevik]

Are you searching for an element that has a specific grandchild? Or an element that has any grandchild?

If the former, I think this would work: a/*/c/../..
If the latter, I think this would work: a/*/*/../..

[LeeSmet]

I was indeed referring to the first case. Also this solution does work for me, thanks