Complex sentence: At that time, Joseph Robert was the chief perfumer at "Chiris" and since there were little prospects of promotion for Beaux, he tried to use his contacts to the emigrated Russian nobility to get new projects.
Split into simpler sentences: At that time, Joseph Robert was the chief perfumer at "Chiris". With littleprospect of promotion under him, Beaux, Beaux tried to use his contacts to the emigrated Russian nobility to get new projects.