"filled" with the Spirit is a pretty broad term.
Folks in the Old Testament were "filled" with the Spirit or "full" of the Spirit like Joshua (
Deut 34:9) and Gideon (
Judges 6:34) and Bezalel (
Ex 31:1-5).
John the Baptist was "filled" with the Holy Spirit before birth (
Luke 1:15, 41-44) and so were his parents Elizabeth and Zechariah (
Luke 1:41, 67). The Apostle Peter said that the Spirit of Christ was in the OT prophets (
1 Peter 1:11).
Jesus told His disciples to wait in Jerusalem until they were baptized in the Spirit. This Spirit baptism is similar to water baptism i.e. an immersion, saturation, overwhelming, soaking, etc). On the Day of Pentecost it says they were filled (
Acts 2:4). Then later it is said that Peter was "filled" while addressing the Jewish leaders (
Acts 4:8) and still later a whole group of them were filled as they prayed (
Acts 4:31). Filling can and does happen many times. In
Ephesians 1:13 it says the Ephesian believers had been sealed with the Holy Spirit but Paul exhorts them to "be filled" or "keep getting filled" or "be ongoingly filled" with the Spirit in
Eph 5:18.
As someone else has pointed out there are many operations of the Holy Spirit on us like
regeneration or birthing
filling and refilling
baptism in the Spirit
etc
Many folks have been saved/regenerated (born of the Spirit) before they were baptized in the Spirit.