1) obs1 = Observable.of(["abc","xyz"]
2) obs2 =Observable.of({
    id:123;
    value:"company";
    name: abc;
})

obs3= Observable.combineLatest(
obs1,
ob2,methodToProcess
);

methodToProcess(obs1, obs2) {
return {
first:obs2.name !== 'a'? obs2: {
...obs2,
name: obs1.includes('a') ? 'a' : obs1[0]
}
};
}

obs4 = Observable.of(sessionStorage.getItem("name");