this way is good for just tow word :
the code must be :
(\bword1\b.+\bword2\b|\bword2\b.+\bword1\b)

so for tree word :

(\bword1\b.+\bword2\b.+\bword3\b|\bword1\b.+\bword 3\b.+\bword2\b|\bword2\b.+\bword3\b.+\bword1\b|\bw ord2\b.+\bword1\b.+\bword3\b|\bword3\b.+\bword2\b. +\bword1\b|\bword3\b.+\bword1\b.+\bword2\b)

i think this way for tree or more word is not good..
..