This happenend last August 22nd in Belgium. Some days ago, the MP parish of Namur (a town in Belgium) received Saint Seraphin relics from Russia. On August 22nd, they were lent to the catholic monastery of Chevetogne in Belgium. Chevetogne is a catholic monastery that uses Byzantine and benedictine rites.
Then, catholics served a moleben with Saint Seraphin relics using the Byzantine rite. It was presided by the Catholic bishop of Namur.
You can access this information in French and Russian on the site
www.archiepiskopia.be Choose your language (French or Russian) and click on the information of August 22nd.
This a photography but there are more on the site