Consider a series of disjoint sets which map a label to one or more GCIs. Each GCI begins as a singleton.

{05A06F01}
{05A9291B}
{05B4EC32}
{05A0C703}

You already have the functionality to union additional GCIs under their PLMN and eNB ID (which becomes the set parent).

{310120, 05A06F, {05A06F01, 05A06F02, 05A06F03}}
{310120, 05A929, {05A92919, 05A9291A, 05A9291B}}
{310120, 05B4EC, {05B4EC31, 05B4EC32, 05B4EC33}}
{310120, 05A0C7, {05A0C701, 05A0C702, 05A0C703}}

Consider instead allowing an arbitrary label to be assigned to any set.

{"NL03XC042", {05A06F01, 05A06F02, 05A06F03}}
{310120, 05A929, {05A92919, 05A9291A, 05A9291B}}
{310120, 05B4EC, {05B4EC31, 05B4EC32, 05B4EC33}}
{"NL13XC116", {05A0C701, 05A0C702, 05A0C703}}

You would still represent the sets internally by some serial ID number, but it would be transparent to the user.

sitedb=# select id, parent, label, plmn, band, sector, gci, pci, tac from sitelog order by parent, label nulls last, sector, band;
 id | parent |     label     |  plmn  | band | sector |   gci    | pci |  tac
----+--------+---------------+--------+------+--------+----------+-----+-------
  1 |      1 | NL03XC042     |        |      |        |          |     |
  2 |      1 |               | 310120 | 25   | 1      | 05A06F01 | 126 | 11524
  3 |      1 |               | 310120 | 25   | 2      | 05A06F02 | 295 | 11524
  4 |      1 |               | 310120 | 25   | 3      | 05A06F03 | 464 | 11524
  5 |      5 | 310120_05A929 |        |      |        |          |     |
  6 |      5 |               | 310120 | 26   | 1      | 05A92919 | 126 | 11574
  7 |      5 |               | 310120 | 26   | 2      | 05A9291A | 295 | 11574
  8 |      5 |               | 310120 | 26   | 3      | 05A9291B | 464 | 11574
  9 |      9 | 310120_05B4BF |        |      |        |          |     |
 10 |      9 |               | 310120 | 41   | 1      | 05B4BF31 | 9   | 11524
 11 |      9 |               | 310120 | 41   | 2      | 05B4BF32 | 10  | 11524
 12 |      9 |               | 310120 | 41   | 3      | 05B4BF33 | 11  | 11524
 13 |     13 | NL13XC116     |        |      |        |          |     |
 14 |     13 |               | 310120 | 25   | 1      | 05A0C701 | 108 | 11524
 15 |     13 |               | 310120 | 25   | 2      | 05A0C702 | 277 | 11524
 16 |     13 |               | 310120 | 25   | 3      | 05A0C703 | 446 | 11524
(16 rows)

The user would then have the ability to union disjoint sets under a common parent and set its label accordingly.

sitedb=# select id, parent, label, plmn, band, sector, gci, pci, tac from sitelog order by parent, label nulls last, sector, band;
 id | parent |   label   |  plmn  | band | sector |   gci    | pci |  tac
----+--------+-----------+--------+------+--------+----------+-----+-------
  1 |      1 | NL03XC042 |        |      |        |          |     |
  2 |      1 |           | 310120 | 25   | 1      | 05A06F01 | 126 | 11524
  6 |      1 |           | 310120 | 26   | 1      | 05A92919 | 126 | 11574
 10 |      1 |           | 310120 | 41   | 1      | 05B4BF31 | 9   | 11524
  3 |      1 |           | 310120 | 25   | 2      | 05A06F02 | 295 | 11524
  7 |      1 |           | 310120 | 26   | 2      | 05A9291A | 295 | 11574
 11 |      1 |           | 310120 | 41   | 2      | 05B4BF32 | 10  | 11524
  4 |      1 |           | 310120 | 25   | 3      | 05A06F03 | 464 | 11524
  8 |      1 |           | 310120 | 26   | 3      | 05A9291B | 464 | 11574
 12 |      1 |           | 310120 | 41   | 3      | 05B4BF33 | 11  | 11524
 13 |     13 | NL13XC116 |        |      |        |          |     |
 14 |     13 |           | 310120 | 25   | 1      | 05A0C701 | 108 | 11524
 15 |     13 |           | 310120 | 25   | 2      | 05A0C702 | 277 | 11524
 16 |     13 |           | 310120 | 25   | 3      | 05A0C703 | 446 | 11524
(14 rows)