SNRB for the tax year 2022-23

Hi,
“For basic rate taxpayers the savings income nil rate band for the tax year 2022-23 is 1000 ,for higher rate taxpayers is 500.additiional rate taxpayers do not benefit from any saving income nil rate band”

basic rate taxpayers are below the threshold of 37700, should it be looked at from the total income or from the savings income ?
if non savings income is 5000 ,savings income is 33000 , so the total income meets the threshold critera , hence a higher rate tax payer , or should we look at the savings income of 33000 and hence a basic rate tax payer
should we apply the basic rate of SNRB of 1000 or higher rate of 500?

Thank you.