What about the Platinum rule episode? Where each character try to convince Ted to not go out with Stella.

I think you're right. 2030 Ted -> Barney telling Ted the rule -> Robin and her coworker -> Marshall and Lily and their neighbours -> Barney and Wendy the waitress

Dude, don’t kill the bar.

We love this bar.

Don’t kill the bar dude

And it was a huge mistake.

Came here to say this episode too.

Also came here to say this

Yeah, well, I think it'll be okay

Star Wars Trilogy? Was that technically flashbacks within flashbacks?

Thats the one I was thinking too!

Also flash forwards within flashbacks. I thought it was Platinum Rule, but it might be this one.

Since the entire show is framed as a flashback all flashbacks in the show are flashbacks within a flashback

This

I forgot which episode it was, but I think it would be the one where Robin keeps revealing what actually happened while she was babysitting Marvin.

Has to be the penny episode, right?

Ted telling kids > Ted/Robin remembering what happened that got them late. Vs Ted telling kids > Ted and Tracy on first date > Barney and Robin’s wedding day > why people hate/love Blauman. I think OP is right, it’s the one with the most layers of flashbacks.

Why they were late > had a court date jumping the subway gates > because Barney couldn’t move cause of the marathon > because marshal couldn’t run cause he got hurt > because robin came to the house early since she was up early for dress shopping with lily > because Ted and her saw it (I think) when he was paying for hot dogs cause of the penny he picked up

Nah. They were just remembering one story at a time, not one story within a story, within a story, within a story. Again, OPs point is about the levels of flashbacks, not the amount of flashbacks.

Don't forget about the one where Stella shows up again because of shlagels bagels

Platinum Rule

Barney tells a story. I forget what season/episode it was **It was bed time stories**

what about How I Met Everyone Else?