Finding the origin of a text in the source code has to be done manually:
Use GUID to find the corresponding property file (path information) in table /UI5/TREP_FILES; the GUID corresponds to the field PROP_FILE_GUID.
The translator sees a key for each text element, which is a concatenation of the text type and another GUID. This GUID corresponds to the field PROP_TEXT_GUID in table /UI5/TREP_TEXT; here you can find the text name for a particular GUID.
The developer can use this text name to search in the corresponding project in Eclipse to find the location where this particular text is used.