The file links you’re displaying in the embedded base represent what Obsidian’s registered as the outgoing links (for each file the base returns based on your filter(s)) .
It’s the unfiltered value of all the outgoing links … including the .base files… and it can’t be modified directly…
So, if you wish to filtered out the .base files from the value of file.links and display it in your embedded base, you can only do so by adding a formula property which would output file.links minus the .base files…
You would then display the “file links formula property” instead of Obsidian’s implicit key file links.
That’s what this implied:
… Sorry if I wasn’t clear enough …
The formula I shared before wasn’t meant to be used as a filter but as a possible answer to your question:
If you look at the screenshot here, you’ll see that the first column is the same file links from your last screenshot: It’s Obsidian’s implicit key file.links which displays the .base files, as its value is unfiltered …
The last field/column, on the other hand, is a formula property in which the .base files have been filtered out from file.links with this formula: