I think the Paragon Path and Epic Destiny of 4e was a broadly good idea. When you enter a new major tier of play, you make a choice that defines your character for that tier.
For 5e, having such a decision to make around 10th or 11th level would be good. At that point the game becomes much broader in focus. The options provided would reflect how your character relates to the larger world in some way.
Such a thing could probably be integrated into 5e via through a Prestige Feat, which is pretty much just a feat with prerequisites such as level, class, or in-world organization. They would probably often tie in with creating strongholds, having retainers or subjects, and generally exerting influence on the world. Examples include:
- Guild Master (start or take over a small guild)
- Warlord (start a military force geared toward conquering land)
- Archmage
- Templar
- Inquisitor
- Tax Collector
- Forge Master
- Magical Lab Owner