What is the filename of an embedded OLE- object?

In a writer (odt) document I have inserted an calc-sheet OLE-object. The procedure to embed this OLE-object I have to give in the filename of the CALC-sheet. Afterwards now, I have forgotten this filename. How do I get this filename?

If you inserted it with a link you should find it under menu Edit → Links to External Files…
If you didn’t link and thus merely embedded it there is no such thing.