Not unique fields

Good day I'm starting to work out with the principle of One Box robots, and myself as an addendum Contact The problem is that I cannot add one contact as a manager for two companies. TOV "Company 1" Director Ivanov Ivan Ivanovich tel. 0505555555 TOV "Company 2" Director Ivanov Ivan Ivanovich tel. 0606666666 TOV "Company 3" Director Ivanov Ivan Ivanovich tel. 0606666666 In theory, I am guilty of mother contact 1. Ivanov Ivan Ivanovich tel. 0505555555 2. Ivanov Ivan Ivanovich tel. 0606666666 3. TOV "Company 1" -> manager Ivanov Ivan Ivanovich tel. 0505555555 4. TOV "Company 2" -> manager Ivanov Ivan Ivanovich tel. 0606666666 5. TOV "Company 3" -> manager Ivanov Ivan Ivanovich tel. 0606666666 Do not follow such a scheme in me First, the system from the drop-down list does not show 2-oh Ivanov Ivan Ivanovich in the manager field, but only one According to a friend Ivanov Ivan Ivanovich, it is not possible to add up to