The Peace Cleric's Emboldening Bond feature can temporarily bond creatures together giving a d4 bonus to rolls. The effect is as follow:
While any bonded creature is within 30 feet of another, the creature can roll a d4 and add the number rolled to an attack roll, an ability check, or a saving throw it makes. Each creature can add the d4 no more than once per turn.
The class feature, however, does not specify if you use this ability before or after you see the roll?
Note that the official ruling by Sage Advice for Flash of Genius (in the thread marked as duplicate) relies on the specific terminology and timing of a "Reaction". Emboldening Bond is not a reaction so this ruling doesn't appear to apply.
Similarly Divine Soul Sorcerer's Favoured by the God's feature. It is the most similar buff to Emboldening Bond (also adding d4's without a reaction). However, it clearly specifies that it can be used "after" a failure. One would have to assume the absence of this specification in Emboldening Bond implies a different ruling?
Favoured by the Gods [...] If you fail a saving throw or miss with an attack roll, you can roll 2d4 and add it to the total, possibly changing the outcome.