Are there any remote job board for jobs without any location barrier?

Location independence depends mainly on the employer-employer or client-contractor relationship, not the job or company. For the right person most jobs have no location requirement.

Some companies have hard rules about working in the office. You can determine that policy by calling and asking HR. Most companies don’t have such policies and decide case-by-case.

Of the various ways to find a job, searching job boards and send in applications ranks low for efficiency and effectiveness. Getting leads from professional and personal contacts, and through referrals, should be the first approach. If you do that you will already know the remote work rules.

Good question. If there isn't, one should definitely be created.