This configuration is to configure for TDD UL/DL pattern for dedicated UE (i.e, configuration for a specific UE, not common to every UE). You can apply this configuration for a slot that is not used by TDD UL/DL common configuration.

NOTE : I haven't seen any real network scenario that enable this (at least as of Apr 2024). I am not sure if any UE modem would support or not.

tdd UL/DL Dedicated Configuration (tdd-UL-DL-ConfigDedicated)
TDD-UL-DL-ConfigDedicated ::=       SEQUENCE {
    slotSpecificConfigurationsToAddModList      SEQUENCE (SIZE (1..maxNrofSlots)) 
                                                          OF TDD-UL-DL-SlotConfig    OPTIONAL
    slotSpecificConfigurationsToreleaseList     SEQUENCE (SIZE (1..maxNrofSlots)) 
                                                         OF TDD-UL-DL-SlotIndex       OPTIONAL
}

TDD-UL-DL-SlotConfig ::=            SEQUENCE {
    slotIndex                           TDD-UL-DL-SlotIndex,
    symbols                             CHOICE {
        allDownlink                         NULL,
        allUplink                           NULL,
        explicit                            SEQUENCE {
            nrofDownlinkSymbols                 INTEGER (1..maxNrofSymbols-1)     OPTIONAL,  
            nrofUplinkSymbols                   INTEGER (1..maxNrofSymbols-1)     OPTIONAL  
        }
    }
}

TDD-UL-DL-SlotIndex ::=             INTEGER (0..maxNrofSlots-1)

slotIndex : Identifies a slot within a dl-UL-TransmissionPeriodicity (given in tdd-UL-DL-configurationCommon)

symbols : The direction (downlink or uplink) for the symbols in this slot(the slot specified by slotIndex)

explicit : indicates explicitly how many symbols in the beginning and end of this slot are allocated to downlink and uplink, respectively.

nrofDownlinkSymbols : Number of consecutive DL symbols in the beginning of the slot identified by slotIndex. If the field is absent the UE assumes that there are no leading DL symbols.

nrofUplinkSymbols : Number of consecutive UL symbols in the end of the slot identified by slotIndex. If the field is absent the UE assumes that there are no trailing UL symbols.

Meaning of each parameter in this RRC IE can be illustrated as below.

Reference

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