I wrote a formula for a field Target per Month per Opportunity owner that should populate with currency when an opportunity has a certain close date month.
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=1) ,139.043,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=2) ,141.617,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=3) ,149.341,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=4) ,164.791,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=5) ,180.240,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=6) ,185.390,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=7) ,200.839,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=8) ,195.690,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=9) ,218.862,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=10) ,226.588,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=11) ,244.611,
IF( AND( Owner.Id = 0054J000001U0X4QAK, MONTH(CloseDate)=12) ,205.987,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=1) ,64.896,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=2) ,66.098,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=3) ,69.703,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=4) ,76.914,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=5) ,84.124,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=6) ,86.528,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=7) ,93.739,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=8) ,91.335,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=9) ,102.151,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=10) ,105.756,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=11) ,114.169,
IF( AND( Owner.Id = 0054J000001U0QGQA0, MONTH(CloseDate)=12) ,96.142,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=1) ,28.338,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=2) ,28.914,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=3) ,30.491,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=4) ,33.645,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=5) ,36.800,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=6) ,37.851,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=7) ,41.005,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=8) ,39.954,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=9) ,44.685,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=10) ,46.262,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=11) ,49.942,
IF( AND( Owner.Id = 0054J000001U0XOQA0, MONTH(CloseDate)=12) ,42.057,
0
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CASE()
as Adrian suggested, but also use a text editor like the free Visual Studio Code that will do parentheses matching.