Well the obvious thing is to combine your for..in loop with your .filter() function:
var x = [{name: "one", swp: "two"}, {name: "two", swp: "three"}, { name: "aa", swp: "bb"}];
var filtered = x.filter(function(v) {
for (var k in v)
if (v[k] === "two") return true;
});
console.log(filtered);