Not sure about BarCap specifically but rough guide: MD> Senior VP> VP> Assistant VP> Senior Associate> Associate> Analyst
Can take years to move up the ladder and the toughest jumps are at Associate to VP, and from VP to MD. Associates/analysts essentially do the grunt work. VPs still do some grunt work, but are expected to start doing more relationship building, winning business and generating leads. Usually MDs will almost never get their hands dirty (unless everyone else really ****s up) and are more focused on client relationships and winning business. There is more above MD but I doubt he will ever get that far, and there a varying levels of VP/MD and their responsibilities, all depends tbh. It's not too far removed from an accounting or law firm hierarchy.
Btw, your relationship is going to end in tears if you place so much value in this kind of meaningless stuff. Dating someone for their job title is ridiculous, I should start calling myself Chief Finance Forum Moderation Officer.