In 5E, there are only a handful of sources for magic items that are official.
The Dungeon Master's Guide - primarily the Dungeon Master's Guide, and the Appendicesappendices of published Adventuresadventures.
After looking through all of these, the answer to your question is: No. The Blinkback Belt does not have an exact equivalent in D&D 5eNo. The Blinkback Belt does not have an exact equivalent in D&D 5e.
There are a few magic items that have a similar effect though (in that they can be thrown multiple times). However, all of these return the item to your hand, not your belt - a small but perhaps noteworthy difference.
From the DMG:
- The Dwarven Thrower Dwarven Thrower (Very Rare Warhammer, only usable by a dwarf) can can be thrown, and immediately immediately flies back to your hand afterwards.
- WhelmWhelm is a legendary sentient Warhammer (only usable by a dwarf) that has the same feature
From Princes of the ApocalypsePrinces of the Apocalypse adventure:
- A Storm BoomerangStorm Boomerang returns to your hand if you miss (but not if you you hit)
Finally, In the adventure Waterdeep: Dragon Heist there is a new magic item called the Bracer of Flying Daggers that functions similarlyclosest to what you're looking for is probably in the Blinkback Beltadventure (albeit more limited in what weapons can be equipped to it, but allowing an extra attack).Waterdeep: Dragon Heist:
- The Bracer of Flying Daggers functions similarly to the Blinkback Belt (albeit more limited in what weapons can be equipped to it, but allowing an additional attack):
This armband appears to have thin daggers strapped to it. As an action, you can pull up to two magic daggers from the bracer and immediately hurl them, making a ranged attack with each dagger. A dagger vanishes if you don’t hurl it right away, and the daggers disappear right after they hit or miss. The bracer never runs out of daggers.