anymore = ya no mas (in the not longer way) so if you say i haven't see him anymore = no lo he visto más ( where no -at the beggining- and más -at the ending are both part of the translation for anymore, notice that más is not always said in a negative sence so may say something like "lo he visto más" which will mean "i have see him again")

Yes, anymore could means más. The sentence "No lo he visto más" is correct but had better to say "No lo he vuelto a ver más" or "No he ido al parque más veces"

"No lo he visto nunca más", "No he ido al parque nunca más"

anymore = YA (NO)

Ya no lo he visto (a él) / Ya no he estado en el parque (ya no he ido al parque)