The associated file for Progression tables is Progressions.lsx. Progression tables are used to assign various resources to a race, subrace, class, or subclass. These can be things like Action Resources, spells, passives, and more.
Each Progression table has 2 UUIDs associated with it:
UUID
node.TableUUID
<node id="Progression">
<attribute id="Boosts" type="LSString" value="ProficiencyBonus(SavingThrow,Wisdom);ProficiencyBonus(SavingThrow,Charisma);Proficiency(LightArmor);Proficiency(MediumArmor);Proficiency(HeavyArmor);Proficiency(Shields);Proficiency(SimpleWeapons);Proficiency(MartialWeapons);ActionResource(LayOnHandsCharge,3,0);ActionResource(ChannelOath,1,0)" />
<attribute id="Level" type="uint8" value="1" />
<attribute id="Name" type="LSString" value="Paladin" />
<attribute id="ProgressionType" type="uint8" value="0" />
<attribute id="Selectors" type="LSString" value="SelectSkills(627af380-2bbb-4a9f-9571-5ec781a6daf4,2);AddSpells(fb407d81-3a05-46f1-9153-0fb27dce95b6,,,,AlwaysPrepared);SelectAbilityBonus(b9149c8e-52c8-46e5-9cb6-fc39301c05fe,AbilityBonus,2,1)" />
<attribute id="TableUUID" type="guid" value="ba2afe85-acba-4ea1-a238-2b4543f47821" />
<attribute id="UUID" type="guid" value="b60618d1-c262-42b5-9fdd-2c0f7aa5e5af" />
<children>
<node id="SubClasses">
<children>
<node id="SubClass">
<attribute id="Object" type="guid" value="b36d247e-d39f-4ae9-9476-3ec315c55789" />
</node>
<node id="SubClass">
<attribute id="Object" type="guid" value="1c761ad0-6f5f-409e-ac1d-ddf6f85c1fc4" />
</node>
<node id="SubClass">
<attribute id="Object" type="guid" value="3cc3d397-c47d-4966-87ae-88827f73f645" />
</node>
</children>
</node>
</children>
</node>
<node id="Progression">
<attribute id="AllowImprovement" type="bool" value="True" />
<attribute id="Boosts" type="LSString" value="ActionResource(LayOnHandsCharge,1,0)" />
<attribute id="Level" type="uint8" value="4" />
<attribute id="Name" type="LSString" value="Paladin" />
<attribute id="ProgressionType" type="uint8" value="0" />
<attribute id="TableUUID" type="guid" value="ba2afe85-acba-4ea1-a238-2b4543f47821" />
<attribute id="UUID" type="guid" value="4f2c7b4e-2f91-4105-a136-9387a8cfed4f" />
</node>
The UUID b60618d1-c262-42b5-9fdd-2c0f7aa5e5af is exclusively used to reference the non-multiclass Level 1 Paladin Progression node. UUID 4f2c7b4e-2f91-4105-a136-9387a8cfed4f, on the otherhand, references the Level 4 Paladin node.
The TableUUID ba2afe85-acba-4ea1-a238-2b4543f47821 references EVERY base class Paladin Progression node. It is used in the Multiclass Level 1 node, Level 4 node, Level 12 node, etc.