I have been studying about Kama and Rati for some time. Before I get slammed about who and what I should be studying I just want to say this is only research.. I just research things.. it's for informational purposes.. Last time I I posted a question about Rati I got slammed about not focusing on her and I should focus my study on Krishna or someone like that..

My question is what is Shiva and Shaktis relation to Kama and Rati?

Rati(elder) & sati(Shakti) are both daughters of Prajapati Daksha.

Sridhara Maharaja has stated ,as others have,
that Shiva is the state of consciouness
that is freedom from all material contaminations
and misconceptions, the highest state of consciousness
in this world.

In the brahma samhita, shiva is described in relation
to krishna as milk is to yogurt.

in the material world shiva does the work of krishna.

Shakti in the context you used ,i assume refers to Durga,
who is the expansion of Lakshmi, who is the expansion
of Radha.

she is also Shiva's consort.