I would like to find a Latin sentence similar to 'Veritas est intellectus rei adequatio' but with Amor instead of Veritas.
The original quote from Thomas Aquinas (quoting an earlier philosopher) is:
Veritas est adaequatio rei et intellectus.
Truth is the equation of the thing and the understanding.
In other words, a statement is true if it corresponds to a fact about reality.
If you just want to swap in amor for veritas, you get a grammatically correct sentence:
Amor est adaequatio rei et intellectus.
Love is the equation of the thing and the understanding.
But I'm not sure this is what you want. Could you clarify the intended meaning? Do you want one understanding to be set equal to another, for example, or do you want to set the understanding equal to something else?
(I know requests for clarification are supposed to be comments, not answers, but this was too long for a comment.)