Custom validation of dependent fields

[emarkovskyi]

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[ ] Bug report
[] Feature request
[ ] Regression (something that used to work, but stopped working in a newer version)
[x ] Support request
[x?] Documentation issue or request

Is it possible to implement some custom validation rule for dependent fields?
so for example I want to check that some 'width' field is greater than or equal to 'height' field
The idea to store this inside schema as a validation rule, and do not handle this by "onChanges" for example
Txs!