If you haven’t heard or seen the most recent update to the SDK tool Configuration Migration Tool (CMT) then it is a must check out as the latest version of the tool includes filtering capaibility as Alan Mervitz (@amervitz) noticed on Twitter and has documented on his blog.
This feature in CMT has been long sought after for years…and years. The basics of the ask were, filter the data prior to exporting, so that you could extract a subset of data. Previously CMT worked in a fashion for an entity that it was all the records or nothing. You can 100,000 contacts in your system, it would attempt to extract all of them. Now you can provide a Fetchxml filter to a data schema definition and have that applied when CMT requests the data from CDS (also known to some as Dynamics 365/CRM…still). You could previously post process exports…
Nishant Rana's Weblog 