The message (wikibase-rc-wikibase-edit-title) is used on watchlists by both the legend box and the hovertext for the "D" letters next to particular items. This results in hovertext like "This edit was made at [[Wikipedia:Wikidata|Wikidata]]" (note the visible wikitext markup).
|Open||None||T96040 Wikibase special pages (tracking)|
|Resolved||Lydia_Pintscher||T98703 [Task] wikibase-rc-wikibase-edit-title should be split into two separate messages|
The content of the message is "Wikidata edit", so what you report looks really strange...
After grepping the code, I have found that this message is only used as this hovertext (tooltip), so in fact no splitting is needed. But where does the wikitext come from, then?
Got it! It comes from MediaWiki:Wikibase-rc-wikibase-edit-title on English Wikipedia, so you only need to change the local page.