Try the following :-
For the first number:-
=mid(Fields!ID.Value,3,instr(Fields!ID.Value,",")-3)
For the second number:-
=mid(Fields!ID.Value,instr(Fields!ID.Value,",")+1,instr(Fields!ID.Value,"]")-(instr(Fields!ID.Value,",")+1))
For the third number:-
=mid(Fields!ID.Value,instr(Fields!ID.Value,"""y"":")+4,instr(Fields!ID.Value,"}")-instr(Fields!ID.Value,"""y"":")-4)
They work for the following set of data:-
[[42016,44969],[{"name":"$41,000/year goal","y":41000}],["",""]]
[[4206,144969],[{"name":"$41,000/year goal","y":41000}],["",""]]
[[4204566,69],[{"name":"$41,560,000/year goal","y":41560000}],["",""]]